Disk drive having a stationary plate facing a disk and with a recirculation filter coupled to grooves in the stationary plate

ABSTRACT

A novel disk drive is disclosed and claimed. The disk drive includes a disk and a spindle motor to which the disk is attached to rotate about an axis of rotation. The disk drive also includes a stationary plate facing and disposed over the disk, wherein the stationary plate includes a plurality of grooves through which rotation-induced air flows from an inlet end to an outlet end. The disk drive also includes a recirculation filter coupled to and immediately adjacent said outlet end of said plurality of grooves.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a Continuation of pending U.S. patent applicationSer. No. 11/305,550, entitled “DISK VIBRATION DAMPER HAVING ANINTEGRATED AIR CIRCULATION GUIDE,” filed on Dec. 16, 2005, which isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION

The invention relates in general to data storage systems such as diskdrives, and in particular to a disk vibration damper having integratedair circulation guide.

Hard disk drives (HDDs) are sensitive to vibration, with the performanceand reliability of an HDD being adversely affected by excessivevibration of the disks. Vibration in hard disk drives (HDDs) can causeread/write errors and/or significant problems with the control andstability of the drive's servo-mechanical system. Disk vibration can beexacerbated by large-scale pressure variations in the airflow that iscaused by disk rotation.

HDDs are also sensitive to particulate contaminates. Accordingly, theairflow caused by disk rotation must be filtered to remove potentiallyharmful particulate matter. To that end, recirculation filters are animportant component of the HDD since particulate matter on disk'ssurface can significantly interfere with the operation of the HDD'sread/write head. Typically, such recirculation filters are placed at alow pressure region off the disk where the airflow tends to migrate.

One method used to dampen disk vibration disks has been to place astationary plate between disks. In addition to serving as a spoiler todestroy large-scale flow features that might lead to large-scalepressure variations, the stationary plate, in conjunction with the air(or other gas) surrounding the disks, also produces a squeezed-filmeffect whereby the compressed air between the individuals disks wouldexert a stabilizing force on the adjacent disks. However, such vibrationdampers have not significantly enhanced the air filtering process. Giventhe HDD market trend towards reductions in both the cost and thephysical size of HDDs, reducing the total part count within the HDD (forexample by somehow providing additional functionality to an existingpart) can significantly enhance the competitiveness of an HDDmanufacturer's product. Thus, there is a need in the art for a diskvibration dampener that also improves the efficiency of the HDDrecirculation filter.

SUMMARY OF THE INVENTION

A novel disk drive is disclosed and claimed. The disk drive includes adisk and a spindle motor to which the disk is attached to rotate aboutan axis of rotation. The disk drive also includes a stationary platefacing and disposed over the disk, wherein the stationary plate includesa plurality of grooves through which rotation-induced air flows from aninlet end to an outlet end. The disk drive also includes a recirculationfilter coupled to and immediately adjacent said outlet end of saidplurality of grooves.

BRIEF DESCRIPTION OF THE DRAWINGS

FIGS. 1A-1B are perspective views of a two-disk implementation of oneembodiment of the invention;

FIGS. 2A-2B are top and bottom perspective views of one embodiment of astationary plate of the invention;

FIG. 3 is a perspective view of a portion of the stationary plate ofFIG. 2B; and

FIG. 4 is a top view showing the relative orientation of a disk,stationary plate and voice coil motor of one embodiment of theinvention.

DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

According to certain embodiments of the invention, a single stationaryplate is disposed between two adjacent disks, wherein the stationaryplate has a grooved side through which rotation-induced air may flow. Incertain other embodiments, a plurality of stationary plates may bedisposed between a plurality of disks, wherein each of the plurality ofstationary plates has a grooved side through which the rotation-inducedair may flow. The stationary plate may be adjacent to the disk forbetween about 30 degrees and about 270 degrees with respect to thedisk's axis of rotation.

In certain embodiments of the invention, the aforementioned grooves havean inlet side and an outlet side, and the width of the grooves at theinlet side is greater than the width of the grooves at the outlet side.In certain embodiments, the grooves gradually taper so as to increasethe air pressure inside the grooves to improve the dampening andsuppressor effect of the stationary plate. In certain embodiments, theangle of the inlet side, as measured relative to the rotational motionof the disk, ranges between 0 degrees and approximately 45 degrees.

In certain embodiments of the invention, airflow from the aforementionedoutlet side impinges upon the disk drive's voice coil motor (VCM),thereby cooling the VCM.

FIGS. 1A-1B depict perspective views of a two-disk implementation of oneexemplary embodiment of the invention. In this embodiment, disk assembly100 comprises an upper disk 110 and a lower disk 120 separated by adistance 130. As is known in the art, the disks rotate about a centralaxis by rotating a spindle motor hub 155 using an attached spindle motor(not shown). While depicted in FIGS. 1A-1B as a two-disk implementation,it should equally be appreciated that the disk assembly 100 similarlymay be comprised of one or more than two disks.

The rotation of disks 110 and 120 causes airflow that can exacerbatedisk vibration, as previously discussed. In order to suppress or dampenthis effect, one embodiment of the invention is to dispose stationaryplate 140 between the top disk 110 and bottom disk 120, as shown in FIG.2. As will be described in more detail below, the stationary plate 140also includes one or more grooves configured to channel this airflowtowards filter 150.

While FIGS. 1A-1B depict only a single stationary plate 140 disposedbetween two disks 110 and 120, it should equally be appreciated that thedisk assembly 100 may include a plurality of stationary plates disposedbetween a plurality of disks, wherein each of the plurality ofstationary plates has a grooved side through which the rotation-inducedair may flow. In one embodiment, the plurality of stationary plates isconfigured so that the grooved side of each plate faces in a commondirection. The disk assembly 100 may have only a single disk, as in thecase of a so-called “depopulated” disk drive, in which case one or twostationary plates may be used.

FIGS. 2A and 2B depict perspective views of the stationary plate 140 ofFIGS. 1A-1B. In particular, FIG. 2A depicts a first side 140 a of thestationary plate 140, while FIG. 2B depicts a second side 140 b of thestationary plate 140. In the exemplary embodiment of FIG. 2A, side 140 ais depicted as having a essentially flat surface 160 which is to beoriented adjacent to but separated from one of the disks 110 and 120 ofFIGS. 1A-1B. In one embodiment, side 160 is separated from an adjacentdisk by no more than approximately 0.5 mm. In addition, FIG. 2A furtherdepicts a filter insert 170 to which a recirculation filter may besecured. FIG. 2B, on the other hand, depicts side 140 b of plate 140,which represents the other side of stationary plate 140 a. In oneembodiment, side 140 b is separated from an adjacent disk by no morethan approximately 0.5 mm.

Side 140 b is further depicted as having a series of grooves 180 throughwhich rotationally-induced air may flow. While in the embodiment of FIG.2B, the plate side 140 b is depicted as having three grooves, it shouldsimilarly be appreciated that the plate side 140 b may have more or lessgrooves. In one embodiment, the plate side 140 b has between one andfifteen grooves. In addition, while the grooves of plate side 140 b areshown as being on only one side of the plate, in another embodiment thegrooves may also be located on plate side 140 a of FIG. 2A.

FIG. 3 is one exemplary embodiment of the area 190 outlined in FIG. 2B.In this embodiment, each groove 180 has an inlet side having an inletwidth 210 a-210 c. In addition, each groove 180 also has an outlet sidehaving an outlet width 220 a-220 c. In certain embodiments, the groove'sinlet widths 210 a-210 c are greater than the outlet widths 220 a-220 c.In addition, the widths of grooves 180 may gradually taper from theinlet widths 210 a-210 c to the outlet widths 220 a-220 c, as shown inFIG. 3. In certain embodiments, the size of the outlet widths 220 a-220c may be between 20% and 80% of the size of the inlet widths 210 a-210c.

In the embodiment shown in FIG. 3, the grooves 180 taper closer to theoutlet end (near filter 200) which causes the air pressure to build upinside the grooves 180. In one embodiment, this increased air pressureimproves the dampening and suppressor effect of the stationary plate140.

In the embodiment shown in FIG. 3, the grooves 180 have a depth 230. Itshould be appreciated that this depth 230 may vary, but in certainembodiments is no greater than 80% of the distance 115 between disks 110and 120 of FIGS. 1A-1B. FIG. 3 further depicts the placement of arecirculation filter 200 within filter insert 170, in the embodimentshown.

It should further be appreciated that recirculation filter 200 maycomprise a known recirculation filter that is capable of removingparticulate matter from the rotationally-induced airflow. In oneembodiment, the recirculation filter 200 may be placed at the outlet endof grooves 180 since this is where much of the rotationally-inducedairflow will travel, as well as to further increase the resistance ofthe airflow to exit, thereby improving the suppressor or dampeningeffect of the stationary disk 140.

FIG. 4 is a top view showing the orientation of a disk 240 and voicecoil motor 250 in relation to the stationary plate 140, in accordancewith an embodiment of the invention. In the embodiment shown, disk 240rotates about axis 245 with stationary plate 140 oriented adjacent tobut separated from the disk 240, as shown in FIG. 4.Rotationally-induced airflow 260 enters grooves 180, as shown in FIG. 4,and exits through filter 200. Moreover, VCM 250 is oriented adjacent tofilter 200 such that rotationally-induced airflow 260 impinges the VCM250. In certain embodiments, this configuration enables the airflow 260to cool the VCM 250.

Airflow 260 enters the grooves 180 at a particular inlet angle,depending on curvature of the grooves 180. In the embodiment of FIG. 4,the inlet angle 270 is measured from horizontal 280 relative to therotational motion of disk 240. In certain embodiments, the inlet angleranges between 0 degrees and approximately 45 degrees.

In certain embodiments, the stationary plate 140 may be adjacent to thedisk 240 for between about 30 degrees and about 270 degrees with respectto the axis of rotation 245. For example, in the embodiment of FIG. 4the stationary plate 140 is adjacent to the disk 240 for approximately110 degrees, as shown by angle 290.

In the foregoing specification, the invention is described withreference to specific exemplary embodiments thereof, but those skilledin the art will recognize that the invention is not limited thereto. Itis contemplated that various features and aspects of the above-describedinvention may be used individually or jointly and possibly in anenvironment or application beyond those described herein. Thespecification and drawings are, accordingly, to be regarded asillustrative and exemplary rather than restrictive. The terms“comprising,” “including,” “with,” and “having,” as used herein, areintended to be read as open-ended terms.

1. A disk drive comprising: an upper disk; a lower disk; a spindle motorto which the upper disk and lower disk are attached to rotate about anaxis of rotation; a stationary plate disposed between said upper diskand lower disk, said stationary plate comprising a plurality of groovesthrough which rotation-induced air flows from an inlet end to an outletend, a top side facing said upper disk, and a bottom side facing saidlower disk; and a recirculation filter coupled to and immediatelyadjacent said outlet end of said plurality of grooves, wherein the inletend of one of the plurality of grooves is closer to the axis of rotationthan the outlet end of the same groove.
 2. The disk drive of claim 1,wherein said inlet end has an inlet angle of between 0 degrees and 45degrees relative to a rotational motion of an adjacent disk to the inletend.
 3. A disk drive comprising: an upper disk; a lower disk; a spindlemotor to which the upper disk and lower disk are attached to rotateabout an axis of rotation; a stationary plate disposed between saidupper disk and lower disk, said stationary plate comprising a pluralityof grooves through which rotation-induced air flows from an inlet end toan outlet end, a top side facing said upper disk, and a bottom sidefacing said lower disk; and a recirculation filter coupled to andimmediately adjacent said outlet end of said plurality of grooves, and avoice coil motor positioned adjacent to said recirculation filterwithout any intervening structure where said rotation-induced airimpinges on said voice coil motor.
 4. A disk drive comprising: a disk; aspindle motor to which the disk is attached to rotate about an axis ofrotation; a stationary plate facing and disposed over said disk, whereinthe stationary plate includes a plurality of grooves through whichrotation-induced air flows from an inlet end to an outlet end; and arecirculation filter coupled to and immediately adjacent said outlet endof said plurality of grooves, wherein the inlet end of one of theplurality of grooves is closer to the axis of rotation than the outletend of the same groove.
 5. The disk drive of claim 4, wherein said inletend has an inlet angle of between 0 degrees and 45 degrees relative to arotational motion of said disk.
 6. A disk drive comprising: a disk; aspindle motor to which the disk is attached to rotate about an axis ofrotation; a stationary plate facing and disposed over said disk, whereinthe stationary plate includes a plurality of grooves through whichrotation-induced air flows from an inlet end to an outlet end; and arecirculation filter coupled to and immediately adjacent said outlet endof said plurality of grooves, and a voice coil motor positioned adjacentto said recirculation filter without any intervening structure wheresaid rotation-induced air impinges on said voice coil motor.